For example, paragraph [0003] of JP 2012-190639 A (Patent Literature 1) describes the following. The non-aqueous electrolyte battery, in which the electrolyte solution is composed of a non-aqueous electrolyte, undergoes a deterioration of battery performance when water vapor enters the inside of the battery. On the other hand, gases, such as hydrogen and carbon dioxide gases, are generated by the decomposition of the electrolyte solution during charge and discharge, or when overcharged, or when stored at high-temperature, causing the battery case of the non-aqueous electrolyte secondary battery to swell. This publication proposes that a selective permeation part formed of a fluorine-based resin that allows carbon dioxide to permeate while restricting permeation of water vapor is provided on a battery case of the non-aqueous electrolyte secondary battery (see claim 1). The publication mentions that the “fluorine-based resin” may be polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PTFE), and ethylene-tetrafluoroethylene copolymer (ETFE) (see claim 5).
Specific examples of the positive electrode active material of the non-aqueous electrolyte secondary battery that are listed in this publication are lithium-containing composite oxides, such as LiCoO2, LiNiO2, LiMn2O4, and LiNiy Co1-yO2 (0<y<1). In addition, it is stated that it is also possible to use a solid solution in which part of the transition metal element is substituted by another element, and that examples thereof include LiNi0.5 Co0.5O2 and LiNi0.8 Co0.2O2 (see paragraph [0021]). Moreover, it is stated that, in the case of the lithium-ion secondary battery described therein, the overcharge detection voltage is set to 4.20 V±0.05 V, and the overdischarge detection voltage is set to 2.4 V±0.1 V (see paragraph [0086]).
In addition, JP 2002-158008 A (Patent Literature 2), for example, discloses a non-aqueous electrolyte secondary battery in which the maximum operating potential of the positive electrode is 4.5 V or higher versus metallic lithium.